What type of reaction occurs in the first committed step of glycolysis?

In glycolysis, the first committed step is catalyzed by the enzyme phosphofructokinase-1 (PFK-1), which phosphorylates fructose-6-phosphate to fructose-1,6-bisphosphate using ATP as a phosphate donor. This specific reaction is a phosphorylation reaction because it involves the addition of a phosphate group to the substrate.

The significance of this step lies in its regulation and the commitment it represents to the glycolytic pathway. Once fructose-1,6-bisphosphate is formed, the pathway continues to proceed, making this step critical for controlling the rate of glycolysis. The use of ATP in this step signifies that energy is being utilized to move the process forward, emphasizing the role of phosphorylation in metabolic pathways for activation and regulation.

Other types of reactions, such as oxidation or hydrolysis, do not accurately describe what occurs during this step, as they involve other mechanisms and functions within biochemical pathways.